1. Field of the Invention
The present invention relates to apparatus for retouching components, especially turbomachine rotor blades, without dismantling the whole assembly to which they belong, and also to a retouching process constituted by the method of using the said apparatus.
2. Description of the Prior Art
When inspecting a turbomachine after it has been operating, especially in the case of an aeroengine subject to strict acceptance criteria imposed by the conditions of use, or when checking during maintenance, one or more strictly localized defects may sometimes be found on the surface of some of the rotor blades. These defects ar generally in the form of pits with or without a slight thickening at the edges, and have the appearance of impact marks, slight cuts or material fault marks. Their size is limited to a few tenths of a millimeter. The acceptance of the damaged blade or of the rotor assembly which includes it requires a retouching of the defect with a view to smoothing the edges of the affected area. This type of retouching, requiring the use of a tool for the removal of material, has hitherto necessitated dismantling the assembly concerned, particularly in the case of a multistage compressor, which leads to substantial down times and results in the immobilization of equipment and high costs.
It is also known to use a apparatus for observation and checking of components in areas which are not directly accessible, particularly inside turbomachines or other assembled units. U.S. Pat. No. 4,078,864, FR-A-2 443 697, FR-A-2 561 399 and U.S. Pat. No. 4,659,221 describe examples of the application of these known techniques; but they do not provide any satisfactory solution for the retouching and the correction of defects which can be seen only with the aid of an endoscope.